Safety ski binding



April 1o, 1945. A. M CILVAINE l SAFETY SKI BINDING Filed Aug. 1942 ffy-5 f5 /5' /0/ m wm RM E O N Te R MWA X Patented Apr. 10, 1945 UNITED STATES PATENT OFFICE SAFETY sx1 BiNmNG VAlexander Mcllvaine, New York, N. Y.

Application 4August 1, 1942, Serial No. 453,195

' (Cl. 28o-11.35)

9 Claims.

My present invention relates to safety skibindings and aims to provide certain improvements therein.

Safety skil bindings, as heretofore made and used, have not for one reason or another proved to' be entirely satisfactory to release the ski from a skiers boot under lconditions where such release is desirable to prevent a bad sprain to the skiers anklefor a fracture 0f the skiers leg. The deciencies of the prior safety bindings are due, wholly or in part, to the fact that said devices respond to the sidewise thrust generated primarily at the ball of the foot which gives rise to the opening' of the clamping means or toe irons at the wrong time and, frequentlyjduring the making of a perfectlyv normal turn.

My present invention seeks to provide a ski binding which will overcome the deficiencies aforementioned. In its underlying concept my invention primarily resides in the provision -of an oblique pivotal mounting for the clamping means'or toe irons, such that a greater force will be required yto move a toe iron outwardly at the rear or ball of the foot portion than at the forward end.A The advantage which flows from such an arrangement is that the ski inv twisting relatively to the boot under severe stress will allow the toe of the boot to open one of the toe irons to release the ski from the boot whereas a sidewise thrust resulting fromfordinary skiing activities will be resisted by the clamping means ai; the rear end thereof which is adjacent the hinges to retain the ski on the boot. My invention also contemplates other features of novelty which will become apparent from the detailed description which follows when considered in connection with the accompanying drawing wherein: e

Fig. 1 is a side elevational view of a part of a ski having a, boot ysecured to it by the binding device of the present invention.

Fig.,2 is a top .plan `view on a somewhat enlarged scale of the ski binding shown in Fig. 1, with parts thereof broken away and omitted.

Fig. 3 is a side elevational view of the ski binding showing the toe iron at the side of the ski opposite to that shown in Fig. 1.

Fig. 4 is a sectional view taken along` the plane of the line 4-4 of Fig. 2.

Fig. 5 is a longitudinal sectional view taken along the plane of the line 5--5 of Fig. 6 and showing a modification of the boot-toe stop means shown in Fig. 2.

Fig. 6 is a fractional top plan view of the adjustable boot-toe stop means shown in Fig. 5.

Referring to the drawing and more particularly to Figs. 1 to 4 thereof, the numeral ID represents a fractional part of a ski on the top face of which is mounted a ski binding of my present invention which comprises in part a pair of upwardly extending clamping members or toe irons II and IIa, which are secured to the ski in such spaced relation as to define a forwardly tapering recess for receiving and holding the toe portion of a boot I2 against lateral movement on the ski. To accommodate boots 'of different width, the toe irons II andIIa are mounted on separate base plates I3 which may be adjustably secured `to the ski by a cover plate It by screws I5 adapt- 1 ed to extend through transverse slots I6 in the cover plate, In order that the cover plate may securely hold the base plates in preadjusted position, the adjacent faces of the base plates and the cover plate areprovided with longitudinally extending intertting grooves and ribs.

Each of the clamping members or toe irons II and IIa is of generally elongate form and is hingedly mounted with respect to the side of the skialong an axis which extends obliquely downwardly from its rear forwardly, said hinged connection being formed at the rear edge of the toe iron as shown at II. Above the hinge I' each toe iron is formed with an extension or tongue I8 adapted to laterally iiank the sole of the ski boot and at its forward upper end is formed with an offset projecting tongue or lug I9 or IBa which is perforated and receives freely therethrough the shank of a screw 20 having a winged head 2i for facilitating the manual turning of the screw. For normally urging each of the toe irons upwardly and inwardly about its hinged mounting, there is provided a coil tension spring 22, one end of which is formed with a loop which is hooked through an opening in the forward end of the cover plate M in proximity to the side edge thereof and the other end of which has a nut 23 affixed thereto and within which the screw 2U engages. From an inspection of Fig. 4 of the drawing, it will be apparent that the springs 22 cross one another and extend corresponding tongue |911. on the toe iron IIa.

The toe irons II and IIa are provided or formed with suitable means forholding the toe of the boot sothat it may not rise therein, and, as herein shown, themeans for accomplishing this are inwardly directed struck-'up ribs 24 and 24a.. The toe irons Yare also preferably formed with inturned tongues or lips 25 and 25a, the bottom edges of which contact the cover plate I4 for reinforcing and preventing the bending upwardly thereof by the force of the springs and for limiting the forward movement of the boot within the toe clamp.

For supporting the toe irons in the oblique hinged relation to the sides of the skis as aforementioned, the base plates I3 are preferably formed with lateralwings 26 extending beyond the sides of the ski and having downwardly and, preferably, outwardly directed flanges 26a, the rear edges of which are curled inwardly to form tubular portions complemental to those of theV hinge Il at the rear edge of the toe irons for accommodating hinge pins (not shown).

Conventional means may be employed for urging and holding the boot in cooperative relation to the toe irons, and, as herein shown,l said means consist of a coil spring 21. looped around the heel ofthe boot and secured at its opposite ends to a pair of cables 28, of`which only one is here shown, which cables extend along the opposite sides of the ski under clips 29 to some point forward of the toe clamping means where they are secured to a toggle 3U which serves as a convenient means for tightening the cables at the time that the ski is bound to the boot and, of course, for loosening the cables when the ski is to be removed. In order that some limited degree of adjustment for the ski binding be provided to accommodate boots of different sizes in length, the usual threaded connection 3l between the ends of the spring 21 and the adjacent ends of the cables 28 may be relied upon.

In Figs. 5 and 6 I have shown an alternate method of providing an adjustment for accommodating boots of different length. As shown in said figures, a stop member at the forward end of the binding is made adjustable longitudinally of the ski relatively to the toe clamp. This adjustable stop is in the form of an L-shaped member 32, the foot of which is longitudinally slidable in an elongate recess 33 in the forward end of the cover plate lll, there being a hole through the foot portion of the stop through which a screw 34 serves to anchor the adjustable stop in desired position within the recess 33.

In the operation of the ski binding hereinbefore described, the boot is secured to the ski by engaging the coil spring 2l around the heel of the boot l2, thus urging the toe portioninto the forwardly tapering recess defined by the clamping members or toe irons ll and lla. The springs 22 are made strong and are tensioned to hold the toe irons in engagement with the extension sole of the boot to support the toe portion of the boot against lateral mvement on the ski under such stresses that are encountered in ordinary ski activity. When, however, the skier trips or falls, thus tending to apply excessively greater stress to his legs and ankles, the pressure of the boot against the toe iro-ns rises to apoint where, if it overcomes the tension of the spring 22 of a particular toe iron, will cause said iron to swing about its oblique pivot to force said `toe be subjected. Under normal skiing activity, however, such as in making turns and the like, the lateral stress and sldewise thrust, which primarily takes place at approximately the ball of the foot, is directed against the rear of the toe irons, and, in view of the oblique arrangement of the hinge connection, such stress exerts on said toe irons but a minimum leverage action which is normally insuicient to turn it about its pivot to release the ski from the boot. Under excessive stress, such for example, as when the skier trips or falls, the forward or rear end of the ski may be subjected to an excessive lateral thrust, the force of which acting on the forward end of a toe iron provides a great leverage action with respect to the hingeand operates to open one or the other of the toe irons to release the foot from the ski.

Although I have shown and described a preferred embodiment of my invention, it is to be understood that I do not wish to be limited to the specific details of construction disclosed since these may be varied within the range of engineering skill without departing from the spirit of the invention as defined in the accompanying claims.

What I claim is:

1. In a safety ski binding, a toe clamp comprising a pair of upwardly extending clamping members each of which is hingedly mounted with respect to the sides of the ski along .an axis which extends obliquely downwardly from its rear forwardly and spring means normally biasing said clamping members to hold them in an upwardly and inwardly extending position with respect to the top face of the ski.

2. In a safety ski binding, a toe clamp comprising a pair of upwardly extending clamping members each of which is hingedly mounted with respect to the sides of the ski along an axis which extends obliquely downwardly from its rear forwardly and independent spring means normally biasing each of said clamping members to hold them in an upwardly and inwardly extending position with respect to the top face of the ski.

3. A safety ski binding according to claim 2., wherein each 0f the spring means is a tension spring connecting the forward upper end of the clamping member to the transversely opposite side of the ski.

4. A safety ski binding according to claim 2,y

wherein each of the spring means is a tension spring connecting the forward upper end of. the clamping member to the transversely opposite side ofthe ski and each of the springs being provided with manually operable means for varying the tension thereof.

5. A safety ski binding according to claim 2, wherein the hinged connection of each of the clamping members is at the rear thereof.

6. A safety ski binding according to claim 2, wherein each clamping member is hingedly connected to a base plate which is rigidly mounted on the ski and has a part extending laterally outwardly and downwardly with respect to the top face of the ski and the rear edge of said downwardly extending part constituting a part of the hinged connection Ifor the clamping member.

7. A safety ski binding comprising a toe clamp having a pair of upwardly extendingv clamping members each of which is hingedly mounted with respect to the sides of the ski along an axis which extends obliquely downwardly from its rear forwardly and has inwardly directed means for engaging over the extension sole of a ski boot, spring means biasing said clamping members to hold wherein the stop means are integrally formed on them in an upwardly and inwardly extending pothe clamping members. stion with respect to the top face of the ski and 9. A safety ski binding according to claim '7, stop means adjacent the forward end of the toe wherein the stop means is adjustable longitudi- Clamp fOr engaging the forward end of the ex- 5 nally of the ski relatively tothe toe clamp. tension sole of the ski boot.

8. A safety ski binding according to claim 7, ALEXANDER MCILVAINE. 

